"To watch the thousands of people that stood in front of this sign...having selfies, taking group photos, then watching them on social media sending this sign back around the globe, was something to behold," he said.

"The task will begin now of working towards what we can do in terms of permanent signage."

The Brisbane City Council and state government will team up on the design and implementation of a permanent sign, but Mr Walker said there was no estimate yet of cost.

"We'll be looking at whatever way we need to make sure that while we get a good display and long term memory of G20, we do so in a cost-effective way," he said.

The initial plan for the sign was for the materials used in construction to be broken up and recycled.

As is, the materials will last until February/March before degrading.

Mr Walker said the design team would factor in key issues like presentation and surviving the elements.

"It's an important thing to pick up the key features of the sign that was there, but to do it in a way that's going to be permanent," he said.

"It's got to be able to survive floods and all of the weather here on South Bank...I'm sure that's not beyond the wit of our designers and engineers."

Mr Walker said the government was also taking feedback on the Colour Me Brisbane lighting display via Premier Campbell Newman's Facebook page, to see whether there was also a case to revive that in some form in the future.

The director of the G20 cultural program Athol Young said the Brisbane sign was a personal favourite.

"We wanted to create something that was a clear representation of our city and something that would put us on the world map and I think we've definitely achieved that," Mr Young said.

"[It's] a testament to what a community can do when it comes together to create something positive."